Scratch built Brodak Strega with Saito 72 for power. Hints and tips

[Ivan Bolton]

I am seriously considering  a scratch built Brodak Strega for my next project.  I want to use a Saito 72 with the UHP control line conversion.  Are there any particular modifications I could/should make to this airframe when scratch building.  (I am conscious of watching the weight)   For example does the nose need to be shortened and perhaps the tail moment lengthened  to get it to balance with this heavier motor??  I would be grateful for any building tips/advice/shared experiences  as far as this airframe and engine combination  is concerned.   Thanks

[Brett Buck]

I am seriously considering  a scratch built Brodak Strega for my next project.  I want to use a Saito 72 with the UHP control line conversion.  Are there any particular modifications I could/should make to this airframe when scratch building.  (I am conscious of watching the weight)   For example does the nose need to be shortened and perhaps the tail moment lengthened  to get it to balance with this heavier motor??  I would be grateful for any building tips/advice/shared experiences  as far as this airframe and engine combination  is concerned.   Thanks

   

    Get the plans, and make sure you use the airfoil from the original, NOT the ARF airfoil. The LE radius should be at least 1/2"

    Brett

[Brad Smith]

Brett what needs to be done to arc wing i have one im starting on?

[Ivan Bolton]

The plans are on the way hopefully.   Surprising that the plan and the ARC/ARF rib sections are different.

[Brett Buck]

Brett what needs to be done to arc wing i have one im starting on?

     The LE is *way* too sharp. If you have an ARF/ARC, round off the LE as much as you can without going through the sheeting. The stock ARF airfoil stalls very easily even in benign conditions.

   Brett

[Brad Smith]

Should it be blunted or rouned off.

[Ivan Bolton]

Well I have spent the last month in the workshop and the Strega is now built, finished and ready for testing.   I used 3/8" square on the leading edge so that I could round it off well as per all the comments I read about it being too sharp.  I shortend the nose by 1" for the Saito 72 and it balances nicely, so I won't need to put any weight into the weight box I built into the tailend of the fuselage!!  The Saito has a UHP C/L manifold set fitted.   It now needs some let up in our horrible weather so that I can test it.

 I have found this article helpful and intend to use its advice in running the Saito.  http://flystunt.com/ARTICLES/4stroke.htm  The tank is built as per the recommendations therein.

Thanks for the help

[MarcusCordeiro]

Looks very nice!!

Marcus

[Randy Powell]

I like it.

[john e. holliday]

Looks great.  Should fly great also.

[Brian Massey]

That should be a good combination. I'm interested in how you like the Saito; I"ve got two 62's waiting for airframes.

Brian

[Bob Reeves]

Well I have spent the last month in the workshop and the Strega is now built, finished and ready for testing.   I used 3/8" square on the leading edge so that I could round it off well as per all the comments I read about it being too sharp.  I shortend the nose by 1" for the Saito 72 and it balances nicely, so I won't need to put any weight into the weight box I built into the tailend of the fuselage!!  The Saito has a UHP C/L manifold set fitted.   It now needs some let up in our horrible weather so that I can test it.

 I have found this article helpful and intend to use its advice in running the Saito.  http://flystunt.com/ARTICLES/4stroke.htm  The tank is built as per the recommendations therein.

Thanks for the help

Can't believe I've somehow missed this thread. That article by Brad is quite old, a couple of us have taken his start and fine tuned it into what has evolved into what works much better and is allot more consistant. If you have checked out the 4 stroke section you will see we are now even running reverse pitch props.

http://www.tulsacl.com/SaitoCarb.html

http://www.tulsacl.com/ReverseSaito.html

[SteveMoon]

That looks great Ivan. I think you'll find the Strega/Saito combination a good one.
You should have no problem at all getting consistent runs with the UHP manifold/venturi
set. I've used them for years with great results.

Steve

[proparc]

Ivan,
The guys over at the 4 stroke forum would sure appreciate a more in-depth review of your plane and engine setup. If you have any more photos\and or comments, we sure would like to see it.

[Ivan Bolton]

Here are a couple more pictures of the model.  The wing was built in two halves in an Adjustojig: it's a big beast!!  Fuel will be Omega 20% Coolpower patten fuel.  There is a very limited range of pattern fuel here in Ireland, i.e. just Coolpower!!  The Saito 72 has had a chequered history: it was originally in a Great Planes Venus mini pattern R/C model and it then survived a workshop fire caused by a lipo!!  I have a selection of wooden props on the way to try out.  There is an APC 13X6 on it for the pictures.  I will try it out as soon as the cold windy weather here in Ireland clears.  I use pusher props on some of my eclectics with good results so I am very interested in the comments on reversing the Saito!!

[proparc]

You scratched built a Big Jim Patternmaster, and used a Saito big block reclaimed from a fire. Ivan, as far as I am concerned, as to you being a modeler, you my friend, are the genuine real deal. Congratulations!!

[Ivan Bolton]

Thank you.  In our miserable climate there is lots of time for building:  winter, spring, autumn and"summer".  Since I retired I get a huge amount of satisfaction/pleasure/fulfillment from scratch  building,  only matched by the satisfaction I get when the weather finally clears enough to get some flights and F2B practice in.  The Saito was lucky enough not to be "cooked"  or water damaged in the fire like 99%  of the rest of my motors, models etc.  I'll post in the four stroke forum as I get experience (or experience problems!!)  in handling this motor.  I love 4 strokes and look forward to this application to C/L

Ivan